When making a new jar item that uses an unsealed block model the resulting model looks incorrect, not sure if this is due to the way the item creation is handled or with the underlying model.

Item Declaration
event.create('crabbersdelight/jar_of_pickles_unsealed', 'tfc:jar')
.placedModel('kubejs:block/crabbersdelight/jar_of_pickles_unsealed')
.displayName('Unsealed Jar of Pickles')
.texture('kubejs:item/crabbersdelight/jar_of_pickles_unsealed')
.tag('tfc:jars')

Block Model
{
"parent": "tfc:block/jar",
"textures": {
"1": "minecraft:block/moss_block",
"2": "tfc:block/jar_no_lid"
}
}

Unable to reproduce with the following code

StartupEvents.registry('item', e => {
    e.create('jar', 'tfc:jar')
        .placedModel('kubejs:block/test_jar');
    e.create('topped_jar', 'tfc:jar')
        .placedModel('kubejs:block/topped_jar');
})

ClientEvents.highPriorityAssets(e => {
    e.addModel('block', 'kubejs:test_jar', m => {
        m.parent('tfc:block/jar');
        m.textures({
            "1": "tfc:block/jar/banana",
            "2": "tfc:block/jar_no_lid"
        });
    });

    e.addModel('block', 'kubejs:topped_jar', m => {
        m.parent('tfc:block/jar');
        m.texture("1", "tfc:block/jar/banana");
    });
})

The broken translucency seems to be a TFC problem and the weird textures may be due to the resource pack you appear to have

thanks for the prompt response! I decided to not use this so I haven't had the time to check this out but I see it works